Ecumenical Chess

Charles Gilman

Introduction

This family of games combines two ideas for "completing" games. One is the addition of a colourbound counterpart to the Knight as the Bishop is to the Rook as in Modern Kamil and Wildebeest Chess. The other is addition of every compound of two FIDE elemental piece as in Bird's, Capablanca's, Carrera's, Grand, and Grander Chess, to name a few. Ecumenical Chess has the fourth kind of elemental piece and all six compounds of two of the four.

Versions of Ecumenical Chess

So far I have devised three games using this combination of pieces.

Simple Ecumenical Chess

SIMPLE Ecumenical Chess has 10 ranks by 8 files. The Pawns have an initial double step.

Pawnless Ecumenical Chess

PAWNLESS Ecumenical Chess uses a FIDE board with no Pawns but the two ranks of pieces rearranged to prevent any initial Rook move. I have tried different front ranks, but in this one the only pieces initially en prise are Camels, with two pieces covering each, and few players will wish to lose a Bishop for a Camel. The combination of the lack of Pawns and the proportion of empty cells guarded by both armies gives this variant a "straight-to-midgame" character. Many pieces will be traded early, and much will turn on deciding which to trade.

Reinforcement Ecumenical Chess

REINFORCEMENT Ecumenical Chess has a 12 by 12 board. The term reinforcement refers to the elemental pieces on the first rank being reinforcements for those on the second. This is because their mobility (Camels apart) is likely to be limited for even more moves than the pieces immediately in front of them - although a 1st-rank Bishop could move into the space vacated by a 2nd-rank Knight.

I have now added several Twin-board subvariants of Ecumenical Chess. These have a page of their own as they are unified by all having 16 Pawns aside and 128 cells.

General Rules

The rules of Ecumenical Chess are identical to those of FIDE Chess, except where noted otherwise below. Pawns, when present, are promotable to any other capturable array piece on reaching the back rank.

Castling requires that the King has not left the middle two files, the Rook involved has not left its own and the adjacent file, neither has left the back two ranks, and both are on the same rank. The King moves 1/4 of the total number of files (3 in the largest, 2 in the others) towards the Rook, and the Rook moves to be adjacent to the King on the inner side. Note that this takes the King off its group of four squares and so disallows castling with a second Rook.

The Pieces
The fourth elemental piece is a 3:1 leaper called the Camel, whose Square Of Leap Length (SOLL) is twice the Knight's. Ecumenical Chess has two Camels aside, the same number as
other elementals, except the Reinforcement version, which has four of every elemental aside to preserve the numerical prevalence of elementals from the inspiring games and FIDE Chess itself.
The extra compounds of FIDE pieces are variously named but my preferences are Marshal and Cardinal. These are popular names among game inventors and I have already used them in some forms of Fivequarters and, with good reason, in Magna Carta Chess. Ecumenical Chess has one of each per side, the same number as Queens.
Another compound with an existing name is the Gnu (Knight+Camel), also known by
other names including the exact synonym Wildebeest. Ecumenical Chess has one Gnu per side, the same number as Queens.
The other two compounds are not historic ones. The CANVASSER (Rook+Camel) is a pun suggestion someone packing tents on a camel, but really means someone carrying out surveys from house to house - though not necessarily houses as grand as that represented by the Rook! The CALIPH (Bishop+Camel) is a title of leaders in early Islam, and that religion spread widely on lands with camels. It is the presence of this piece with Bishops and Cardinals that inspires the name Ecumenical Chess. The latter piece features under another name in Mark Hedden's Ganymede Chess. Each army has one Canvasser but two Caliphs, the latter piece being colourbound. This fact makes the Caliph remarkably weak for a compound - but conversely remarkably strong for a colourbound piece!

Equipment

Most of these can be played with two standard sets distinguishable by size, although Reinforcement EC requires a second small set. I suggest large King/Queen as themselves, small King/Queen as Cardinal/Marshal (cf Magna Carta Chess), other small pieces as themselves, large Pawns as Camels, and other large pieces as their Camel compounds.

Alternative Pieces

You may be wondering why I add further names starting with Ca-, when there are two already. The answer is to extrapolate to longer leapers, looking ahead to possible variants on the 12x12 or yet bigger boards with such leapers and their compounds. The bigger the board the weaker Knights and Camels become.

Groups of alternatives start with a colourswitching/colourbound pair and their triangulating compound. From Ungulates Outwards includes examples such as Zebra+Zemel=Zebu and others where the compound ends in U. There is one example of a 3d trio, 2:2:1 Ninja + 4:1:1 Nimel = Nintu, used alongside the standard trio in a 3d offshoot of this, Ecumenical Eurasian Ninjachess. Diverse Directions includes examples of each pair's compounds with the Bishop and Rook. All can be physically represented as would their Knight/Camel equivalents.